Bulgarian electricity sector in 2034 - domination of renewables, new gas fired capacities and focus on the transmission capacities

On 30 July 2025, the Bulgarian Energy and Water Regulatory Commission (EWRC) will hold an open hearing to consider the ten-year network development plan (TYNDP) for the Bulgarian electricity transmission system operator (ESO EAD).

Like ENTSO-E, the TYNDP is a comprehensive infrastructure plan for electricity grids, coordinated at the EU level. These plans are crucial for ensuring a secure, efficient, and integrated energy system, particularly for bringing renewable energy sources and facilitating an efficient energy market.

The main findings in Bulgaria’s draft TYNDP (2025-2034) developed by the ESO EAD and considered by the EWRC include the following:

1. By 2034, the country's gross electricity consumption will not exceed 41,600 GWh.
2. Bulgaria’s expected maximum electrical load in 2034 is 7,680 MW, and the maximum load for an average working day is 6,800 MW.
3. Renewable energy in gross electricity consumption in 2034 is expected to exceed 50%. Implementing energy efficiency measures will help achieve the national indicative targets. Instead of investing in the construction of new renewable energy plants, it will be possible to invest in reducing energy intensity.
4. The high penetration of non-synchronous RES and decommissioning of existing lignite-fired power plants will reduce electrical system security for the round-the-clock maintenance of frequency and exchange capacities, maintenance of voltage within permissible limits, system stability and inertia, and suppression of low-frequency fluctuations of active power.
5. Natural Gas plants (estimated between 1 and 1.5 GW) can replace lignite-fired power plants, including ensuring the security and adequacy of the electricity system, while reducing emissions by six to ten times compared to 2019.
6. The implementation of the planned development of the transmission network will ensure the normal operation of the electricity transmission network and the necessary conditions for electricity trading.
7. To maintain the voltages in the power transmission network within the permissible limits, the plan includes installing adjustable shunt reactors (used in high-voltage power systems to stabilise voltage during load variations and improve power system efficiency), with a range of 30 to 80MVAr, which will be connected directly to the 110kV network. In addition, two shunt reactors of 50MVAr will be installed in the tertiary winding of the 400/220kV AT in the Maritsa East substation.
8. The presence of a sufficient number of large synchronous units in the Bulgarian transmission system is a necessary condition for ensuring its stability in an energy mix with a significant number of renewables and battery electricity storage systems. In this regard, it is necessary to provide state support for year-round maintenance of a minimum number of large synchronous units, since their emergency responses are a natural by-product of electricity production.

For more information on Bulgaria’s energy sector, contact your CMS client partner or these CMS experts: Kostadin Sirleshtov, Borislava Piperkova.